Pothos Leaves Turning Brown or Black: 11 Causes & How To Fix Them

Are the leaves of your pothos plant turning brown, black, or developing dry, crispy edges? Or perhaps you found brown spots on the leaves, and you’re not sure what they mean? 

Pothos leaves turn brown or black for several reasons. But unlike yellowing leaves, which can be a typical sign of old age, brown or black foliage is always a cause for concern.

Let’s look at the eleven most common causes, starting with the most likely culprit.  

1.) Watering Issues

Inconsistent watering will stress and weaken your plant. When combined with poor-draining soil, it also creates an environment that is inviting to various species of fungi and bacteria.

However, underwatering and overwatering do not immediately cause browning leaves. This means that if you give your pothos too much or too little water, the leaves won’t suddenly turn brown or black. Instead, they will start turning yellow. 

Keep an eye out for yellowing leaves, as they are the first sign that your pothos plant is struggling. By the time the leaves turn brown, or worse, black, your plant is in serious trouble.

How To Fix It

Watering issues are caused by a mix of lousy soil drainage and how often you water your plant. The best way to prevent them starts with the soil.

Always plant your pothos in a well-draining soil mix. Ideally, at least ⅓ of your potting mix should consist of a material that facilitates drainage, such as perlite, pumice, vermiculite, or pine/orchid bark. 

Allow the soil to dry out slightly between waterings. Test the soil with your fingers, and if the top 2 inches (5 cm) feel dry to the touch, give the plant a good soak. If the soil is still wet, give it a few more days to dry out. 

2.) Phytophthora Root Rot

The most common problem for all pothos plants is root rot caused by a fungus-like organism called black shank (Phytophthora nicotianae).

This soil-borne fungal disease thrives in warm temperatures and moist soil. It spreads easily through water and can live in the soil for several years.

If your pothos is planted in a poor-draining soil mix that stays constantly wet, it will be very susceptible to this disease.

Phytophthora infection starts with the roots, which become soft, black, or dark brown, and develop an unpleasant smell. As the disease progresses, the leaves will start yellowing, then quickly turn brown, then black. 

An easy way to differentiate Phytophthora root rot from other diseases is by looking at how the leaves are turning brown. First, the leaf petiole will turn brown and wilted; then, the brown area will spread out from the base of the leaf to the outer sections.   

How To Fix It

Take the pothos out of the pot as soon as the leaves start turning yellow, especially if the soil looks soaked and compacted. Inspect the roots. If you find any soft, black, or brown roots, use a disinfected blade to cut them.

Remember to disinfect the blade after each cut. 

Throw away the old soil, and rinse the roots with a mix of 1-part 3% hydrogen peroxide and two parts water. Repot the pothos in a fresh, well-draining soil mix, and water moderately for the next couple of weeks.  

Also, avoid using the same container for bottom-watering your pothos plants. If one of them is infected with Phytophthora root rot, reusing the water and the same container will spread the disease to your healthy plants.  

3.) Rhizoctonia Root Rot

Rhizoctonia root rot is another fungal disease that can kill your pothos plants. This disease spreads quickly, especially in warm, humid environments.

Like the Phytophthora root rot, it’s a soil-borne disease and usually infects young plants. It’s also one of the most common reasons pothos cuttings die during propagation.

Rhizoctonia blight damages roots as well as foliage. Symptoms include dark, black spots on the pothos leaves and roots that have turned black and mushy.

How To Fix It

You can use the same treatment method as for the Phytophthora root rot. 

Avoid reusing old soil from your other plants when repotting your pothos to prevent future infestations with Rhizoctonia root rot.

Instead, try using new containers or thoroughly disinfecting the old ones, especially if they’re made of porous material, such as terracotta or unglazed ceramic.   

Provide your plants with excellent air circulation, especially if your home is warm and humid. Also, avoid misting your plants to prevent spreading this disease. 

4.) Bacterial Wilt

Bacterial wit disease is caused by several species of bacteria, such as Ralstonia solanacearum and Erwinia tracheiphila.

This disease is easily transmitted in moist, humid conditions. It also spreads easily if you forget to disinfect your scissors or pruning shears when cutting pothos stems and vines.  

Bacterial wilt symptoms include pothos leaves with black, mushy brown stems and yellow, black, or brown patches.

If you take cuttings from badly infected plants, you can also see the cut section secrete a clear, bacterial ooze.

How To Fix It

There is no cure for bacterial wilt. If your pothos plants become infected, the only thing left to do is throw them out. To be safe, throw out the pots and trays of infected plants as well. 

To prevent it, always sanitize your tools when pruning or trimming pothos plants. Provide good air circulation, and avoid misting or keeping your pothos leaves constantly wet. 

Bacterial wilt is a common problem when propagating pothos cuttings in water. To reduce the risk of infection, change the water at least once a week and regularly wash and disinfect the glass or jar used for propagation.

5.) Bacterial Leaf Spot

Several pathogens cause bacterial leaf spot. It is a common problem in humid environments with poor air circulation. It also spreads quickly from one plant to another, so if your plants are grown close together, there’s a good chance they will all get sick.

Symptoms of bacterial leaf spot can vary, depending on the pathogen that causes them. You may see the pothos leaves are getting brown or black spots with yellow halos.

In some cases, especially if the leaves are frequently wet, you may also find soft, water-soaked spots with a musty, rotten smell. 

How To Fix It

Like bacterial wilt, bacterial leaf spot has no cure. There are no effective treatments for it, which means that your only option is to prevent it. 

See the paragraphs discussing bacterial wilt for more details on preventing and controlling the spread of bacterial leaf spot.

6.) Fungal Leaf Spot

Fungal leaf spot is another common problem for pothos leaves. Several species of fungi cause it, and it’s often found in — you guessed it — humid environments with poor airflow.

This disease spreads rapidly and usually infects plants that are stressed by incorrect growing conditions.

Symptoms of fungal leaf spot include:

• Rusty-brown or black spots.
• Silvery-gray patches.
• Brown or discolored leaves.
• Wilted or distorted foliage.  

How To Fix It

The best way to prevent fungal leaf spot is to provide your pothos with excellent air circulation and avoid getting the leaves wet. Regularly prune your pothos, especially if the top leaves are growing in a compacted cluster. 

Trim and discard infected leaves, then spray your pothos with an organic copper fungicide.  

7.) Scale

If you find small, brown spots on the stems and undersides of your pothos leaves, they are most likely a type of scale. 

These insects are between ⅛ and ⅓ of an inch in size and are covered by a thick shell-like coating.

Like most houseplant pests, they suck sap from the leaves and stem and cause leaf discoloration, stunted growth, and death of the plant.

In addition, scale insects produce a sticky substance called “honeydew,” which encourages the development of sooty mold and further damages your pothos plant. 

Scales can be challenging to detect and can live on your pothos for weeks before you notice them. They’re also challenging to remove because they attach themselves firmly to the leaves and stems.  

How To Fix It

Check the underside of your pothos leaves at least once a week. If you find scale, dip a cotton swab in medicinal alcohol, and use it to rub the scale off. Then mix a solution of 1 part medicinal alcohol and four parts water. Finally, use the solution to spray the leaves once every 5 to 7 days for at least a month. 

8.) Sunburn&Nbsp;

Pothos plants can tolerate direct sunlight in small doses. A couple of hours of early morning sun won’t damage the leaves. Although, the leaves will get scorched if the plants are exposed to the intense midday sun. So, avoid placing them next to a south-facing window. 

Sunburn symptoms can vary. Usually, they start off as discolored, pale yellow leaves. However, in case of prolonged exposure, the pothos leaves will develop brown, crispy patches.

Variegated pothos cultivars are more sensitive to sunburn. This includes cultivars with white variegation, such as Manjula, N’Joy, or Snow Queen pothos.

Meanwhile, cultivars such as Golden Pothos, Neon, or Jade Pothos have a higher tolerance to direct sun.

How To Fix It

Move your pothos out of direct sunlight. Ideally, you want to provide it with bright indirect light. The best location for your plant is about 3 feet away from the window.  

9.) Low Humidity

Pothos plants don’t need lots of humidity to grow. However, if the humidity levels drop below 40%, the leaves will develop brown, crispy edges.

Exposure to hot, dry air will lower the plant’s humidity and cause the leaves’ edges and tips to crisp up. This is a common problem if your pothos sits next to a heating vent or a radiator. 

How To Fix It

The easiest way to increase humidity for your pothos is to keep the pot on top of a pebble tray half-filled with water. Alternatively, you can put a cup of water next to your plant.

The moisture from the evaporating water will give the pothos a humidity boost.

Also, remember to keep your pothos away from hot drafts, especially in winter. 

10.) Fertilizer Salt Buildup

Fertilizer salt buildup is a common problem if you’re using synthetic fertilizers. Most of them are made out of nutrient salts.

These salts can build up in the soil, especially if the fertilizer is not diluted correctly or applied too often. In large amounts, they can cause fertilizer burn.

Common fertilizer burn symptoms include brown, curling leaves, discoloration, and stunted growth. In severe cases, the fertilizers can burn the roots, resulting in root rot.

How To Fix It

Apply fertilizers according to the instructions on the label. Pay close attention to how they should be diluted and how often you need to apply them. Never pour undiluted fertilizer on dry soil — whether synthetic or organic, it will still burn the roots.

If you’re fertilizing your pothos more than once a month, remember to flush out the soil at least once a year.

Then, put the plant in the sink or shower, and water it slowly for 5 to 10 minutes, ensuring the soil is thoroughly soaked. Let the excess water drain for at least half an hour before putting the plant back on its tray or decorative mask.  

11.) Fungicide or Pesticide Damage

Incorrect application of fungicides and pesticides can burn the leaves of your pothos. Also known as phytotoxicity, it can cause scorched leaves, crispy tips and edges, and brown spots. These symptoms are similar to sunburn, fertilizer burn, low humidity, and even root rot and pest damage. 

It doesn’t take long for chemical substances to damage the leaves of your pothos plant. You can see burn marks on the foliage one or two days after spraying with a fungicide or pesticide solution.  

Pothos plants are particularly sensitive to fungicides containing mefenoxam. This can give the leaves a bleached look and burnt, crispy tips. 

How To Fix It

Always use pesticides, fungicides, and any other chemical products according to the instructions on the label. When using them for the first time on a specific plant, test them on a single leaf first.

If you don’t see any discoloration or burn marks after two days, you can use it on the rest of the plant. 

If you accidentally sprayed your pothos with too much pesticide or fungicide solution, rinse the leaves under running water for a few minutes. Badly burnt leaves will not recover, so it’s best just to trim them off. 

Videos

So there you have it; now, if you notice your pothos leaves turning brown or black, you’ll be armed with the correct info to save your plant.

References + Resources

Erwinia tracheiphila – ASM Journals: Link

Phytophthora nicotianae
(black shank) – Link

https://www.fdacs.gov/content/download/11407/file/pp401.pdf

https://edis.ifas.ufl.edu/publication/PP340

https://extension.uga.edu/publications/detail.html?number=B1318